Tool for slitting wire or cable covering



Jamis 1945. w. LINDALL TOOL FOR SLITTING.WIRE OR CABLE COVERING Filed Aug. 9, 1945 m m f 5 5 M Mw W M P wk Patented Jan. 30, 1945 TOOL FOR SLITTING WIRE'OR CABLE COVERING Walter I. Lindall, Saugus, Mass. Application August 9, 1943, Serial No. 498.009

Claims.

The present invention relates to a tool used in slitting covers from shielded wires and is pare ticularly useful for slitting the ends of such electrically insulated conductors, used in wiring electrical apparatus. The invention is particularly applicable to conductors which have metallic shields in the form of graded covers which must be stripped for a short length from. the ends of the conductor, perhaps an inch or more in order that the electrical conductor may be properly joined to the electrical terminal or other conductor.

In the present invention the shield and a portion 'of the insulation may be sliced on a diameter merely by inserting the wire. in the tool and pulling it out. An adjustment may be made for the length of the end to be stripped and the tool may be made to accommodate wires of'difierent 81268.

Other advantages and uses of the present invention will be more readily and fully understood by consideration of the specification set forth below when taken in connection with the drawing showing an embodiment of the same in which Fig. 1 shows the invention partly in section; Fig. 2 shows a section taken on the line 22 of Fig. 1; Fig. 3 shows a section taken on the line 3-3 of Fig. 1; and Fig. 4 shows a view corresponding to a view looking from the left of Fig. l but modified in detail.

In the drawing illustrated in Figs. 1, 2 and 3, the tool essentially comprises an elongated block I in which the wire to be stripped is inserted in a hole at the end, and a second block 2 adjustably mounted on the first block, and carrying a knife blade 3. The block I is provided with a hole or recess 4 extending from one end parallel to the elongated dimension of that block I. This recess is shaped to receive the wire to be stripped and should be just sufficiently larger than the wire to leave sufficient tolerance so that the wire may be inserted at the end and then withdrawn. By this means the wire will be properly held and the slicing of the cover will be in the proper position.

If the hole 4 is too large, then the wire will not be centered properly and may be stripped on the side or in a sector rather than along the diameter. A rod 5 may be positioned at the inner end of the hole 4 and is adjustable along the hole by loosening the set screw 6 and tightening it again after the rod had been placed in the desired position. The set screw 6 engages the rod 5 through a slot 1 in the wall of the bar I. A knife blade 3 is pivoted in the block or bar 2 of the screws 8 and 9 which is substantially of the same cross section as the block I andis mounted inv position overthe end of the bar I, as shown in Fig. 1, by two adjustable mounting screws 8 and 9which' are threaded at Ill and II, respectively, into the top of bar I. through recesses l2 and in the member 2 and are surrounded by cylindrical, coiled springs l5 and I6 which bear against the top of the block I. Look nuts and lock washers I1 and I8; respectively, may be used to lock the screws 8 and 9 in place after they have been set to the desired position. A slot I9'is milled in the central part of the member 2 in alinement with a slot 28"in the member I. The knife 3is pivoted by means of a pin 2| in the walls adjacent to slot I9. The

knife 3 hangs downward through the slot 20$ into hole or recess 4 with the lower edge of the blade directed forward to the forward end of the hole so that a straight end of the knife blade projects at the forward end of the slot into the slot.

Sufficient clearance is given by the walls in the members I and 2 so that as the wire is pushed in the hole 4, the knife blade will be pushed backwards riding over the surface of the cover of the conductor to be stripped. When the wire has been inserted to its full distance so that it abuts against the end of the rod 5, it is pulled forward. This action carries the knife blade forward so that it begins to dig into the cover and assumes the position shown in Fig. l shortly after the wire is being pulled out of the hole. The knife blade thereafter digs into the cover and slices it for the rest of the length to the end of the conductor. The cover may be then pulled over and cut by knife, shears or any other means. It will be noted that the end of the knife blade 22 is inclined forward in the hole 4 so that it will more readily dig into the cover as it is being pulled out.

The top member 2 may be adjusted by means to permit a knife blade 3 to make a cut to any depth desired. If a deeper cut is desired, member 2 is forced closer to the top of the member I, while if a shallow cut is desired, the top bar 2 is backed 01f a bit from the bar I. The device shown in Figs. 1, 2 and 3, may be modified as indicated in Fig. 4 so as to take other sizes of conductors or wires. As indicated in this figure, the member 30 corresponding to the member I may be recessed at the end where the wire is inserted to receive amember 3|, which itself has the hole or perforation 32 in which the wire is inserted. In this case the member 3| is indicated as square in section and has These mounting screws 8 and 9 pass a slot 33 at the top through which the knife blade 34 corresponding to the blade 3 projects. The blade 34 may be supported in the same manner as the blade 3 in Fig. 1.

Various fittings or members 3| may be provided to take care of various wire sizes and these may be inserted as desired Within the member 30 and locked in position by means of the set screw 35. The screws 8 and 9 carried by the member 2 are adjusted in position so that the knife blade 34 will project the desired distance into the perforation 32. In this way a single tool may be made to care for a number of different sizes of wire.

Having now described my invention, I claim:

1. A tool for slitting the cover of shielded wire and cable in preparation for stripping the same comprising an elongated block member having a hole extending longitudinally therein from one end and adapted to receive and support the wire to be stripped, a knife blade, means pivotally supporting said knife blade with the edge extending in an axial direction into said hole,.and means limiting the motion of the knife blade in the direction in which the Wire is to be extracted from said hol whereby said wire may be inserted in said hole and when removed, said shield will be slit.

2. A tool for slitting the cover of shielded wire and cable in preparation for stripping the same comprising an elongated block member having a hole extending longitudinally therein from one end and adapted to receive and support the wire to be stripped, a knife blade, means pivotally supporting said knife blade with the edge extending into an axial direction into said hole, said means comprising an adjustable supporting member supported on said elongated block element, said supporting member having a pin journaled therein on which said knife blade is mounted, and means adjusting said supporting member away from said elongated block member as desired, said blade extending axially into said hole, means limiting the motion of said blade only in the direction that the wire is withdrawn from said hole, whereby said knife may be moved with the wire as it is being inserted in the hole, and

locked from motion as the wire is being extracted from the hole.

3. A tool for slitting the cover of shielded wire and cabl in preparation for stripping the same comprising a member having a hole extending longitudinally therein, adapted to receive and support the conductor to be stripped, said mem ber having a slot extending into the said hole in a longitudinal direction, a knife blade positioned in said slot extending in the said hole, means adjustably pivoting said knife blade in said slot whereby adjustment may be made of the projection of the knife blade into said hole, said hole being formed in a removable bushing adapted to b inserted in said member from the end thereof, whereby different size wires may be used by the use of different bushings.

4. A tool for slitting the cover of shielded wire and cable in preparation for stripping the same comprising means providing a hole adapted to receive and support the wire to be stripped, said means havin a longitudinal slot extending into said hole at one side thereof, a knife blade, means pivotally mounting said knife blade with the unpivoted end projecting into said hole through said slot, said slot being so arranged with reference to said knife blade whereby the blade end may be moved in the direction of movement of the wire as it is inserted into the hole and become locked against motion in the opposite direction beyond a normal position as the wire is being withdrawn.

5. A tool for slitting the cover of shielded wire and cable in preparation for stripping the same comprising a member having a hole to receive and support the wire to be stripped, a knife blade, mean pivotally mounting the knife blade in a position projecting into said hole on a diameter thereof with one corner projecting farther into the hole than the other, said blade being locked from motion in the direction that the wire is withdrawn from the hole, whereby said knife blade may be moved with the wire as it is being inserted in the hole and locked from motion as the wire is being extracted from the hole.

WALTER I. LINDALL. 

